blob: 441975b796fb03d901cef8a63dc3414a3a2b508c [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * arch/s390/kernel/process.c
3 *
4 * S390 version
5 * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
7 * Hartmut Penner (hp@de.ibm.com),
8 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
9 *
10 * Derived from "arch/i386/kernel/process.c"
11 * Copyright (C) 1995, Linus Torvalds
12 */
13
14/*
15 * This file handles the architecture-dependent parts of process handling..
16 */
17
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/compiler.h>
19#include <linux/cpu.h>
20#include <linux/errno.h>
21#include <linux/sched.h>
22#include <linux/kernel.h>
23#include <linux/mm.h>
24#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/stddef.h>
26#include <linux/unistd.h>
27#include <linux/ptrace.h>
28#include <linux/slab.h>
29#include <linux/vmalloc.h>
30#include <linux/user.h>
31#include <linux/a.out.h>
32#include <linux/interrupt.h>
33#include <linux/delay.h>
34#include <linux/reboot.h>
35#include <linux/init.h>
36#include <linux/module.h>
37#include <linux/notifier.h>
38
39#include <asm/uaccess.h>
40#include <asm/pgtable.h>
41#include <asm/system.h>
42#include <asm/io.h>
43#include <asm/processor.h>
44#include <asm/irq.h>
45#include <asm/timer.h>
46
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +020047asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
Linus Torvalds1da177e2005-04-16 15:20:36 -070048
49/*
50 * Return saved PC of a blocked thread. used in kernel/sched.
51 * resume in entry.S does not create a new stack frame, it
52 * just stores the registers %r6-%r15 to the frame given by
53 * schedule. We want to return the address of the caller of
54 * schedule, so we have to walk the backchain one time to
55 * find the frame schedule() store its return address.
56 */
57unsigned long thread_saved_pc(struct task_struct *tsk)
58{
Heiko Carstenseb33c192006-01-14 13:20:57 -080059 struct stack_frame *sf, *low, *high;
Linus Torvalds1da177e2005-04-16 15:20:36 -070060
Heiko Carstenseb33c192006-01-14 13:20:57 -080061 if (!tsk || !task_stack_page(tsk))
62 return 0;
63 low = task_stack_page(tsk);
64 high = (struct stack_frame *) task_pt_regs(tsk);
65 sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN);
66 if (sf <= low || sf > high)
67 return 0;
68 sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
69 if (sf <= low || sf > high)
70 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 return sf->gprs[8];
72}
73
74/*
75 * Need to know about CPUs going idle?
76 */
Alan Sterne041c682006-03-27 01:16:30 -080077static ATOMIC_NOTIFIER_HEAD(idle_chain);
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
79int register_idle_notifier(struct notifier_block *nb)
80{
Alan Sterne041c682006-03-27 01:16:30 -080081 return atomic_notifier_chain_register(&idle_chain, nb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082}
83EXPORT_SYMBOL(register_idle_notifier);
84
85int unregister_idle_notifier(struct notifier_block *nb)
86{
Alan Sterne041c682006-03-27 01:16:30 -080087 return atomic_notifier_chain_unregister(&idle_chain, nb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088}
89EXPORT_SYMBOL(unregister_idle_notifier);
90
91void do_monitor_call(struct pt_regs *regs, long interruption_code)
92{
93 /* disable monitor call class 0 */
94 __ctl_clear_bit(8, 15);
95
Heiko Carstensdce55472007-07-10 11:24:21 +020096 atomic_notifier_call_chain(&idle_chain, S390_CPU_NOT_IDLE,
97 (void *)(long) smp_processor_id());
Linus Torvalds1da177e2005-04-16 15:20:36 -070098}
99
Heiko Carstens77fa2242005-06-25 14:55:30 -0700100extern void s390_handle_mcck(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101/*
102 * The idle loop on a S390...
103 */
Adrian Bunkcdb04522006-03-24 03:15:57 -0800104static void default_idle(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 int cpu, rc;
107
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 /* CPU is going idle. */
109 cpu = smp_processor_id();
Nick Piggin64c7c8f2005-11-08 21:39:04 -0800110
111 local_irq_disable();
112 if (need_resched()) {
113 local_irq_enable();
114 return;
115 }
116
Alan Sterne041c682006-03-27 01:16:30 -0800117 rc = atomic_notifier_call_chain(&idle_chain,
Heiko Carstensdce55472007-07-10 11:24:21 +0200118 S390_CPU_IDLE, (void *)(long) cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 if (rc != NOTIFY_OK && rc != NOTIFY_DONE)
120 BUG();
121 if (rc != NOTIFY_OK) {
122 local_irq_enable();
123 return;
124 }
125
126 /* enable monitor call class 0 */
127 __ctl_set_bit(8, 15);
128
129#ifdef CONFIG_HOTPLUG_CPU
Heiko Carstens1fca2512006-02-17 13:52:46 -0800130 if (cpu_is_offline(cpu)) {
131 preempt_enable_no_resched();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 cpu_die();
Heiko Carstens1fca2512006-02-17 13:52:46 -0800133 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134#endif
135
Heiko Carstens77fa2242005-06-25 14:55:30 -0700136 local_mcck_disable();
137 if (test_thread_flag(TIF_MCCK_PENDING)) {
138 local_mcck_enable();
139 local_irq_enable();
140 s390_handle_mcck();
141 return;
142 }
143
Heiko Carstens1f194a42006-07-03 00:24:46 -0700144 trace_hardirqs_on();
Heiko Carstens77fa2242005-06-25 14:55:30 -0700145 /* Wait for external, I/O or machine check interrupt. */
Gerald Schaeferc1821c22007-02-05 21:18:17 +0100146 __load_psw_mask(psw_kernel_bits | PSW_MASK_WAIT |
Heiko Carstens77fa2242005-06-25 14:55:30 -0700147 PSW_MASK_IO | PSW_MASK_EXT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148}
149
150void cpu_idle(void)
151{
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800152 for (;;) {
153 while (!need_resched())
154 default_idle();
155
156 preempt_enable_no_resched();
157 schedule();
158 preempt_disable();
159 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160}
161
162void show_regs(struct pt_regs *regs)
163{
164 struct task_struct *tsk = current;
165
Al Viro30af7122006-01-12 01:05:50 -0800166 printk("CPU: %d %s\n", task_thread_info(tsk)->cpu, print_tainted());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
168 current->comm, current->pid, (void *) tsk,
169 (void *) tsk->thread.ksp);
170
171 show_registers(regs);
172 /* Show stack backtrace if pt_regs is from kernel mode */
173 if (!(regs->psw.mask & PSW_MASK_PSTATE))
Heiko Carstensd2c993d2006-07-12 16:41:55 +0200174 show_trace(NULL, (unsigned long *) regs->gprs[15]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175}
176
177extern void kernel_thread_starter(void);
178
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +0200179asm(
180 ".align 4\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 "kernel_thread_starter:\n"
182 " la 2,0(10)\n"
183 " basr 14,9\n"
184 " la 2,0\n"
185 " br 11\n");
186
187int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
188{
189 struct pt_regs regs;
190
191 memset(&regs, 0, sizeof(regs));
Gerald Schaeferc1821c22007-02-05 21:18:17 +0100192 regs.psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 regs.psw.addr = (unsigned long) kernel_thread_starter | PSW_ADDR_AMODE;
194 regs.gprs[9] = (unsigned long) fn;
195 regs.gprs[10] = (unsigned long) arg;
196 regs.gprs[11] = (unsigned long) do_exit;
197 regs.orig_gpr2 = -1;
198
199 /* Ok, create the new process.. */
200 return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
201 0, &regs, 0, NULL, NULL);
202}
203
204/*
205 * Free current thread data structures etc..
206 */
207void exit_thread(void)
208{
209}
210
211void flush_thread(void)
212{
213 clear_used_math();
214 clear_tsk_thread_flag(current, TIF_USEDFPU);
215}
216
217void release_thread(struct task_struct *dead_task)
218{
219}
220
221int copy_thread(int nr, unsigned long clone_flags, unsigned long new_stackp,
222 unsigned long unused,
223 struct task_struct * p, struct pt_regs * regs)
224{
225 struct fake_frame
226 {
227 struct stack_frame sf;
228 struct pt_regs childregs;
229 } *frame;
230
Al Viroc7584fb2006-01-12 01:05:49 -0800231 frame = container_of(task_pt_regs(p), struct fake_frame, childregs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 p->thread.ksp = (unsigned long) frame;
233 /* Store access registers to kernel stack of new process. */
234 frame->childregs = *regs;
235 frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */
236 frame->childregs.gprs[15] = new_stackp;
237 frame->sf.back_chain = 0;
238
239 /* new return point is ret_from_fork */
240 frame->sf.gprs[8] = (unsigned long) ret_from_fork;
241
242 /* fake return stack for resume(), don't go back to schedule */
243 frame->sf.gprs[9] = (unsigned long) frame;
244
245 /* Save access registers to new thread structure. */
246 save_access_regs(&p->thread.acrs[0]);
247
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800248#ifndef CONFIG_64BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 /*
250 * save fprs to current->thread.fp_regs to merge them with
251 * the emulated registers and then copy the result to the child.
252 */
253 save_fp_regs(&current->thread.fp_regs);
254 memcpy(&p->thread.fp_regs, &current->thread.fp_regs,
255 sizeof(s390_fp_regs));
256 p->thread.user_seg = __pa((unsigned long) p->mm->pgd) | _SEGMENT_TABLE;
257 /* Set a new TLS ? */
258 if (clone_flags & CLONE_SETTLS)
259 p->thread.acrs[0] = regs->gprs[6];
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800260#else /* CONFIG_64BIT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 /* Save the fpu registers to new thread structure. */
262 save_fp_regs(&p->thread.fp_regs);
263 p->thread.user_seg = __pa((unsigned long) p->mm->pgd) | _REGION_TABLE;
264 /* Set a new TLS ? */
265 if (clone_flags & CLONE_SETTLS) {
266 if (test_thread_flag(TIF_31BIT)) {
267 p->thread.acrs[0] = (unsigned int) regs->gprs[6];
268 } else {
269 p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32);
270 p->thread.acrs[1] = (unsigned int) regs->gprs[6];
271 }
272 }
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800273#endif /* CONFIG_64BIT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 /* start new process with ar4 pointing to the correct address space */
275 p->thread.mm_segment = get_fs();
276 /* Don't copy debug registers */
277 memset(&p->thread.per_info,0,sizeof(p->thread.per_info));
278
279 return 0;
280}
281
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200282asmlinkage long sys_fork(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283{
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200284 struct pt_regs *regs = task_pt_regs(current);
285 return do_fork(SIGCHLD, regs->gprs[15], regs, 0, NULL, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286}
287
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200288asmlinkage long sys_clone(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289{
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200290 struct pt_regs *regs = task_pt_regs(current);
291 unsigned long clone_flags;
292 unsigned long newsp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 int __user *parent_tidptr, *child_tidptr;
294
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200295 clone_flags = regs->gprs[3];
296 newsp = regs->orig_gpr2;
297 parent_tidptr = (int __user *) regs->gprs[4];
298 child_tidptr = (int __user *) regs->gprs[5];
299 if (!newsp)
300 newsp = regs->gprs[15];
301 return do_fork(clone_flags, newsp, regs, 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 parent_tidptr, child_tidptr);
303}
304
305/*
306 * This is trivial, and on the face of it looks like it
307 * could equally well be done in user mode.
308 *
309 * Not so, for quite unobvious reasons - register pressure.
310 * In user mode vfork() cannot have a stack frame, and if
311 * done by calling the "clone()" system call directly, you
312 * do not have enough call-clobbered registers to hold all
313 * the information you need.
314 */
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200315asmlinkage long sys_vfork(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316{
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200317 struct pt_regs *regs = task_pt_regs(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200319 regs->gprs[15], regs, 0, NULL, NULL);
320}
321
322asmlinkage void execve_tail(void)
323{
324 task_lock(current);
325 current->ptrace &= ~PT_DTRACE;
326 task_unlock(current);
327 current->thread.fp_regs.fpc = 0;
328 if (MACHINE_HAS_IEEE)
329 asm volatile("sfpc %0,%0" : : "d" (0));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330}
331
332/*
333 * sys_execve() executes a new program.
334 */
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200335asmlinkage long sys_execve(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336{
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200337 struct pt_regs *regs = task_pt_regs(current);
338 char *filename;
339 unsigned long result;
340 int rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200342 filename = getname((char __user *) regs->orig_gpr2);
343 if (IS_ERR(filename)) {
344 result = PTR_ERR(filename);
345 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 }
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200347 rc = do_execve(filename, (char __user * __user *) regs->gprs[3],
348 (char __user * __user *) regs->gprs[4], regs);
349 if (rc) {
350 result = rc;
351 goto out_putname;
352 }
353 execve_tail();
354 result = regs->gprs[2];
355out_putname:
356 putname(filename);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357out:
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200358 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359}
360
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361/*
362 * fill in the FPU structure for a core dump.
363 */
364int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
365{
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800366#ifndef CONFIG_64BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 /*
368 * save fprs to current->thread.fp_regs to merge them with
369 * the emulated registers and then copy the result to the dump.
370 */
371 save_fp_regs(&current->thread.fp_regs);
372 memcpy(fpregs, &current->thread.fp_regs, sizeof(s390_fp_regs));
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800373#else /* CONFIG_64BIT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 save_fp_regs(fpregs);
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800375#endif /* CONFIG_64BIT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 return 1;
377}
378
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379unsigned long get_wchan(struct task_struct *p)
380{
381 struct stack_frame *sf, *low, *high;
382 unsigned long return_address;
383 int count;
384
Al Viro30af7122006-01-12 01:05:50 -0800385 if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 return 0;
Al Viro30af7122006-01-12 01:05:50 -0800387 low = task_stack_page(p);
388 high = (struct stack_frame *) task_pt_regs(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN);
390 if (sf <= low || sf > high)
391 return 0;
392 for (count = 0; count < 16; count++) {
393 sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
394 if (sf <= low || sf > high)
395 return 0;
396 return_address = sf->gprs[8] & PSW_ADDR_INSN;
397 if (!in_sched_functions(return_address))
398 return return_address;
399 }
400 return 0;
401}
402